Is it Possible to use Debian Squeeze's Multiserver setup for Ubuntu 12.04 Server?

Yes

Maybe

No

Hey guys, its my first time to use ISPConfig 3.0.4. The available Multiserver Setup for ISPConfig was only for Debian Squeeze, but unfortunately, I wanted to use Ubuntu Server 12.04...Is it Possible? Thanks in Advance...

The setup should work for Ubuntu 12.04 as well. I recommend that you compare the installed packages of the different server type with the packages installed in the perfcet setup guide for Ubuntu 12.04, there might be some minor differences. E.g. ig´f I remember, ubuntu requires a additiona package dovecot-mysql which is not required for the debian squeeze setup.